The present invention relates to a motor vehicle with an axle arrangement including two opposite wheel carriers that are connectable to a bodywork of the motor vehicle via links, and a transverse leaf spring connected to the two wheel carriers. The axle arrangement can be used as a front axle or a rear axle in a motor vehicle with four wheels. In addition to US 2003/0122338 A1 or DE 10 2010 042 222 A1, reference is made to EP 0 941 912 B1 as an example of prior art.
In general, axle arrangements with transverse leaf springs are known in the prior art. Such a transverse leaf spring extends in the transverse direction of the vehicle between two wheel carriers. If such a transverse leaf spring is made out of fiber reinforced plastic, in particular carbon fiber reinforced plastic or glass fiber reinforced plastic, a transverse leaf spring is obtained that is stable as well as lightweight. It is furthermore known that such plastic transverse leaf springs must be developed in a forked fashion, e.g. they must be designed so that they have, in the center area between the two wheel carriers, at least two so-called bands that are joined in the end area of the transverse leaf spring or at the latest in the sections thereof that connect to the wheel carriers.
Further prior art in the field of vehicle axle arrangements are the so-called shear fields (see, for example, the initially aforementioned EP 0 941 912 B1), which are transmitted to provide the bodywork structure and/or the body of the vehicle with increased stiffness and/or stability in the axle area (and therefore at the place where forces between the vehicle body and the road on which the vehicle moves are transmitted, as well as, if applicable, forces resulting from the collision of the vehicle with an obstacle). To that end, the shear fields, which generally extend in the transverse direction of the vehicle between the two peripheral areas of the vehicle body and which, when viewed in the longitudinal direction of the vehicle, also have an extension that covers the actual axle arrangement, are suitably fixedly (rigidly) connected to the body of the vehicle, preferably with carriers thereof.
It is an object of the present invention to provide a simplified design for an optimally stiff body or bodywork structure for an axle arrangement having two opposite wheel carriers that are connectable to a bodywork of a motor vehicle via links and a transverse leaf spring connected to the two wheel carriers, wherein the transverse leaf spring is made in one piece of fiber reinforced plastic and has at least two bands spaced apart from each other.
This and other objects of the invention are attained in that the transverse leaf spring is at least partially integrated in a shear field that extends between the two wheel carriers and is fixedly connected to the body or the bodywork of the vehicle at both sides. When viewed in the longitudinal direction of the vehicle, the shear field projects beyond the transverse leaf spring.
The invention therefore relates to an axle arrangement for a vehicle with two opposite wheel carriers that are connected to a bodywork and/or the vehicle body via links. The term “bodywork” or “body” is to be construed broadly here and also includes, for example, individual assemblies such as rear axle carriers, longitudinal chassis beams or cross-members of the vehicle. Furthermore, an axle arrangement according to the invention includes a transverse leaf spring that is connected to both wheel carriers. The transverse leaf spring extends approximately in the transverse direction of the vehicle and is developed in one piece. The transverse leaf spring has two bands (flanges) that are spaced apart. It is provided that the bands run together towards the ends of the transverse leaf spring, e.g. to the connecting points with the wheel carriers. By using the transverse leaf spring with two spaced apart bands, a free space is created between the two bands.
Furthermore, a shear field extends practically between the two wheel carriers. The shear field is connected to the body of the vehicle at both sides. In particular, the shear field extends in the horizontal plane. According to the invention, the aforementioned transverse leaf spring that connects the two wheel carriers is at least partially integrated in the shear field. This means that with appropriate development of the material and/or the geometry of the shear field, a component of the shear field acts as the transverse leaf spring.
Preferably, it is provided that the shear field and the transverse leaf spring are made of fiber reinforced plastic. In particular, glass fiber reinforced plastic or carbon fiber reinforced plastic is used. The transverse leaf spring can be developed at least partially as a material thickness in the shear field. This means that the transverse leaf spring is raised from the remaining component of the shear field, in particular in a vertical direction. The transverse leaf spring has at least two bands that are spaced apart from one another. Because of the plurality of bands running in the transverse direction of the vehicle, the transverse leaf spring can be distributed through multiple material thicknesses on the shear field. The shear field does not have to be designed in one piece together with the transverse leaf spring, but these two elements should constitute a connected component to facilitate assembly as well. To that end, the transverse leaf spring can be suitably laminated onto the shear field, which does not necessarily have to be developed in plastic. The transverse leaf spring can be laminated onto the upper side and/or the lower side of the shear field. Developing the transverse leaf spring in fiber reinforced plastic, in particular in carbon fiber reinforced or glass fiber reinforced plastic, facilitates a stable as well as a lightweight transverse leaf spring.
To then address the aforementioned free space between the so-called bands of the “forked” transverse leaf spring, the free space can be used by other vehicle components, for example the vehicle's power train. The transverse leaf spring is situated in particular in a horizontal plane. Accordingly, a free space developed between two bands of the transverse leaf spring also extends in a horizontal plane. So as to be able to use the free space for additional vehicle components, the free space can have a suitable size. If the free space has a first width in the transverse direction of the vehicle and the entire transverse leaf spring has a second width in the transverse direction of the vehicle, it is furthermore proposed that the first width is at least 60%, preferably at least 70% of the second width. If the free space has a first length in the longitudinal direction of the vehicle and the entire transverse leaf spring has at its longest point a second length in longitudinal direction of the vehicle, then in view of a sufficiently large free space, the first length can have at least 40%, preferably at least 50%, of the second length.
Preferably, an electrical machine extends at least partially between the two bands of the transverse leaf spring. When viewing the axle arrangement in a section perpendicular to the horizontal, at least part of the aforementioned electrical machine is situated between two and/or the two bands of the transverse leaf spring. The electrical machine is, in particular, an electric motor to drive the vehicle. Preferably, the electrical machine can also be operated with a generator. In the arrangement of the electrical machine, it is preferably provided that the armature shaft of the electrical machine is approximately aligned with the hubs of the vehicle's wheels. Accordingly, an armature shaft of the electrical machine is designed for torque transmission to at least one of the wheels. In particular, it may be provided that the electrical machine is arranged between the two wheel carriers, and on both sides of the electrical machine, one armature shaft each leads to the wheel carriers and therefore to the wheels.
A transverse leaf spring according to the invention can be connected to the wheel carriers in a wheel-guided as well as in a non-wheel-guided fashion. For the wheel-guided arrangement, it is provided that the ends of the transverse leaf spring are fixedly connected to the respective wheel carrier. In particular, three additional links are then provided to connect the individual wheel carrier to the bodywork. With a non-wheel-guided arrangement of the transverse leaf spring, the ends of the transverse leaf spring are preferably connected to the wheel carriers via connecting elements that act as pendulum supports. For example, five links are then provided to connect the wheel carrier to the bodywork. Due to the fact that the transverse leaf spring extends laterally over the shear field with extensions, such extensions of the transverse leaf spring can form the connection of the transverse leaf spring to the wheel carriers. For this purpose, the extensions are either connected to the wheel carriers fixedly or, in the case of the non-wheel guided arrangement, connected to the wheel carriers via connecting elements that act like pendulum supports.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.
In all figures, identical and/or functionally identical components are denoted with the same reference symbols.